The real strength of the planets is seen from this divisional chart. The planets' position in the D9 or Navamsa chart improves or strengthens the planets in the birth chart. Navamsha or D9 chart is used as a supplementary chart to the birth chart. For example, It is like cutting a fruit apple and into nine same parts or like cutting a big bread into nine equal pieces. That 30 degrees is further divided into nine equal parts. The total zodiac sign consists of 360 degrees, each sign is arranged as 30 degrees.
Nava means nine, and Amsa means division or fractional division, in Sanskrit.
Navamsa or Navamansh or or D9 consists of two parts. Navamsa Chart is one of the divisional charts and the 16 divisional charts as well.